An in-plane switching liquid crystal display (IPS-LCD) has liquid crystals initially oriented parallel to a glass substrate and at a predetermined angle with respect to an electrode, and a magnetic field oriented parallel to the glass substrate. The IPS-LCD exhibits a smaller difference in refractivity of a liquid crystal according to a viewing angle and a wider angel of view than a TN-mode where a liquid crystal is oriented vertically.
The IPS-LCD breaks down into in-plane switching (IPS), super in-plane switching (Super IPS), and fringe field switching (FFS) according to a mode of an active matrix driving electrode including a pair of electrodes. However, IPS-LCD of the present invention is construed to encompass all of them.
As described above, the IPS-LCD has a liquid crystal oriented in a parallel direction and thus shows little change in refractivity according to a viewing angle. But the IPS-LCD, when viewed from the side, has the liquid crystal arranged asymmetrically, thereby undergoing color-shift in the left and right sides. Also, the IPS-LCD experiences high light leakage at an inclined angle, thus showing a low contrast ratio at the inclined angle.
Korean Patent Publication No. 2005-0073221 discloses an IPS-LCD device in which a wide viewing film including a negative biaxial film and a +C plate is disposed between a liquid crystal cell and a polarized plate to improve contrast characteristics in the front and at an inclined angle and minimize color-shift. However, this related art still exhibits a low contrast ratio in a diagonal direction.